I have a selectbox with horizontal scroll. On hover (mouse over) of the selectable item list, the height is growing by one row height, on every onmouseenter. This is reproducible at all times on IE 9.0.8112.16421

I believe this would be similar issue. How would I get notified on any updates for this?

After a lot of trial and error - it appears the problem relates to the use of CSS & overflow: hidden;

With the Panel baseCls & overCls set to a CSS class with "overflow: hidden" the bug is resolved but a new problem introduced with the scroll bars no longer working - which is not an option due to the un-useability issues of no scroll bars.

However, it seems a work around is if the Accordion layout is changed to "fill : true"
Unfortunately our design requirements are "fill: false" for accordions.

Hence it seems to be an issue with IE9 and the use of accordion with layouts set to "fill: false"

I can appreciate ExtJS 3 not being a priority these days but, any suggestions on what can be done to address this would be welcomed as this has been a bug for a fair while.

I have similiar issues with autoscroll inside a panel here.
IE9.
Inside my panel are textfields.
Panel grows vertically with every character I type.
I can even hold left mouse down and drag to let my panel grow.